INTERDISCIPLINARY STUDIES – EVOLUTION OF HABITATS
* Evolution and History
The evolutionary history of primates can be traced back 65 million years. Anatomically modern humans evolved from archaic Homo sapiens in Africa in the Middle Paleolithic, about 200,000 years ago. By the beginning of the Upper Paleolithic period (50,000 BP [Before Present]), full behavioral modernity, including language, music and other cultural universals had developed. (http://en.wikipedia.org/wiki/Human)
Human Migration
Climate studies show a cooling of the climate in Africa from around 3 million to 2.4 million years ago. This cooler, drier climate would have cut back a significant part of the lush northern African forests, opening up vast areas of grassy plains and restricting the range of australopithids adapted to forest habitats. These grasslands and the many resources they afforded for opportunistic scavenging were the ecological niche invaded by the new species Homo.
But scavenging is a migratory life, tied to the hunting patterns of predators and the herds of game they prey on, to fluctuations in water supplies, to seasonal shifts in the requirements for shelter and plants. The increased stature and brain size of Homo rudolfensis and Homo ergaster suggest humans adapted rather quickly to these new rigors. Successfully coping with fluctuating environments created the skills to adapt to a wider range of new environments, making it feasible for the migratory humans gradually to follow resources and herds of game into an ever widening range of habitats across the Middle East and southern Asia.
Pre-modern migrations:
Historical migration of human populations begins with the movement of Homo erectus out of Africa across Eurasia about a million years ago. Homo sapiens appear to have occupied all of Africa about 150,000 years ago, moved out of Africa 70,000 years ago, and had spread across Australia, Asia and Europe by 40,000 years BC. Migration to the Americas took place 20,000 to 15,000 years ago, and by 2,000 years ago, most of the Pacific Islands were colonized. Later population movements notably include the Neolithic Revolution, Indo-European expansion, and the Early Medieval Great Migrations including Turkic expansion. In some places, substantial cultural transformation occurred following the migration of relatively small elite populations, Turkey and Azerbaijan being such examples.
Early humans migrated due to many factors such as changing climate and landscape and inadequate food supply. The evidence indicates that the ancestors of the Austronesian peoples spread from the South Chinese mainland to Taiwan at some time around 8,000 years ago. Evidence from historical linguistics suggests that it is from this island that seafaring peoples migrated, perhaps in distinct waves separated by millennia, to the entire region encompassed by the Austronesian languages. It is believed that this migration began around 6,000 years ago. Indo-Aryan migration from the Indus Valley to the plain of the River Ganga in Northern India is presumed to have taken place in the Middle to Late Bronze Age, contemporary to the Late Harappan phase in India (ca. 1700 to 1300 BC). From 180 BC, a series of invasions from Central Asia followed, including those led by the Indo-Greeks, Indo-Scythians, Indo-Parthians and Kushans in the northwestern Indian subcontinent.
Other significant migrations include Greek migration from 728 BC, Celtic migration in Europe, Bantu migration in Africa as well as European colonial migrations in the 16th Century.
Modern Migrations – Industrialization
While the pace of migration had accelerated since the 18th century already (including the involuntary slave trade), it would increase further in the 19th century. Manning distinguishes three major types of migration: labor migration, refugee migrations, and urbanization. Millions of agricultural workers left the countryside and moved to the cities causing unprecedented levels of urbanization. This phenomenon began in Britain in the late 18th century and spread around the world and continues to this day in many areas.
Industrialization encouraged migration wherever it appeared. The increasingly global economy globalized the labor market. The Atlantic slave trade diminished sharply after 1820, which gave rise to self-bound contract labor migration from Europe and Asia to plantations. Overpopulation, open agricultural frontiers, and rising industrial centers attracted voluntary migrants. Moreover, migration was significantly made easier by improved transportation techniques.
Transnational labor migration reached a peak of three million migrants per year in the early twentieth century. Italy, Norway, Ireland and the Guangdong region of China were regions with especially high emigration rates during these years. These large migration flows influenced the process of nation state formation in many ways. Immigration restrictions have been developed, as well as diaspora cultures and myths that reflect the importance of migration to the foundation of certain nations, like the American melting pot. The transnational labor migration fell to a lower level from 1930s to the 1960s and then rebounded.
The United States experienced considerable internal migration related to industrialization, including its African American population. From 1910–1970, approximately 7 million African Americans migrated from the rural Southern United States, where blacks faced both poor economic opportunities and considerable political and social prejudice, to the industrial cities of the Northeast, Midwest and West, where relatively well-paid jobs were available. (http://en.wikipedia.org/wiki/Human_migration#The_new_economics_of_labor_migration)
Impact of Migrations on the evolution of Habitat Migration of human groups and population from one region to another also accelerated the evolution or transformation of human habitats. Each migrating group carried new or different traditions and technologies thereby helping transform the habitats of their new settlements. The migrations also resulted in amalgamations of groups to create larger populations, as well as conflicts. Amalgamations and population increases resulted in higher technologies further transforming architecture, agriculture and culture. For example regions historically conquered or dominated by Rome were also culturally and architecturally influenced by the Romans. When settlers from Europe migrated to America and Australia they also carried their culture, religion, technology and architecture with them and transformed the landscape of America and Australia.
One of the biggest problems of modern migration from less developed countries to highly industrialized nations as well as from rural locations to cities is the population explosion in developed countries and urban cities.
High populations in cities have accelerated the development of urban areas resulting also in the transformation of the landscape by dense construction of residential, industrial, commercial and recreational facilities and building, as well as networks of roads and rail.
The end result has been habitat destruction. Habitat destruction is the process in which natural habitat is rendered functionally unable to support the species present. In this process, the organisms which previously used the site are displaced or destroyed, reducing biodiversity. Habitat destruction by human activity mainly for the purpose of harvesting natural resources for industry production and urbanization. Clearing habitats for agriculture is the principal cause of habitat destruction. Other important causes of habitat destruction include mining, logging, trawling and urban sprawl. Habitat destruction is currently ranked as the primary cause of species extinction worldwide. It is a process of natural environmental change that may be caused by habitat fragmentation, geological processes, climate change or by human activities such as the in troduction of invasive species, ecosystem nutrient d epletion and other human activities mentioned below. (http://en.wikipedia.org/wiki/Habitat_destruction) (http://en.wikipedia.org/wiki/Habitat_destruction)
Habitat and population
Early human settlements were dependent on proximity to water and, depending on the lifestyle, other natural resources used for subsistence, such as populations of animal prey for hunting and arable land for growing crops and grazing livestock. But humans have a great capacity for altering their habitats by means of technology; through irrigation, urban planning, construction, transport, manufacturing goods, deforestation and desertification. Deliberate habitat alteration is often done with the goals of increasing material wealth, increasing thermal comfort, improving the amount of food available, improving aesthetics, or improving ease of access to resources or other human settlements. With the advent of large-scale trade and transport infrastructure, proximity to these resources has become unnecessary, and in many places, these factors are no longer a driving force behind the growth and decline of a population. Nonetheless, the manner in which a habitat is altered is often a major determinant in population change.Technology has allowed humans to colonize all of the continents and adapt to virtually all climates. Within the last century, humans have explored Antarctica, the ocean depths, and outer space, although large-scale colonization of these environments is not yet feasible. With a population of over six billion, humans are among the most numerous of the large mammals. Most humans (61%) live in Asia. The remainder live in the Americas (14%), Africa (14%), Europe (11%), and Oceania (0.5%).Human habitation within closed ecological systems in hostile environments, such as Antarctica and outer space, is expensive, typically limited in duration, and restricted to scientific, military, or industrial expeditions. Life in space has been very sporadic, with no more than thirteen humans in space at any given time. Between 1969 and 1972, two humans at a time spent brief intervals on the Moon. As of September 2011, no other celestial body has been visited by humans, although there has been a continuous human presence in space since the launch of the initial crew to inhabit the International Space Station on October 31, 2000. However, other celestial bodies have been visited by human-made objects.
World population estimates milestones (USCB)
Population(in billions)
1
2
3
4
5
6
7
8
9
Year
1804
1927
1960
1974
1987
1999
2012
2027
2046
Years elapsed
-
123
33
14
13
12
13
15
19
Since 1800, the human population has increased from one billion to over six billion. In 2004, some 2.5 billion out of 6.3 billion people (39.7%) lived in urban areas, and this percentage is expected to continue to rise throughout the 21st century. In February 2008, the U.N. estimated that half the world's population will live in urban areas by the end of the year. Problems for humans living in cities include various forms of pollution and crime, especially in inner city and suburban slums.Humans have had a dramatic effect on the environment. As humans are rarely preyed upon, they have been described as superpredators.Currently, through land development, combustion of fossil fuels and pollution, humans are thought to be the main contributor to global climate change. Human activity is believed to be a major contributor to the ongoing Holocene extinction event, which is a form of mass extinction. If this continues at its current rate it is predicted that it will wipe out half of all species over the next century. http://en.wikipedia.org/wiki/World_population ***
Pavan Sukhdev talks about habitats and ecosystems
8802 Interdisciplinary Perspectives
INTERDISCIPLINARY STUDIES – EVOLUTION OF HABITATS
*
Evolution and History
The evolutionary history of primates can be traced back 65 million years. Anatomically modern humans evolved from archaic Homo sapiens in Africa in the Middle Paleolithic, about 200,000 years ago. By the beginning of the Upper Paleolithic period (50,000 BP [Before Present]), full behavioral modernity, including language, music and other cultural universals had developed.
(http://en.wikipedia.org/wiki/Human)
Human Migration
Climate studies show a cooling of the climate in Africa from around 3 million to 2.4 million years ago. This cooler, drier climate would have cut back a significant part of the lush northern African forests, opening up vast areas of grassy plains and restricting the range of australopithids adapted to forest habitats. These grasslands and the many resources they afforded for opportunistic scavenging were the ecological niche invaded by the new species Homo.
But scavenging is a migratory life, tied to the hunting patterns of predators and the herds of game they prey on, to fluctuations in water supplies, to seasonal shifts in the requirements for shelter and plants. The increased stature and brain size of Homo rudolfensis and Homo ergaster suggest humans adapted rather quickly to these new rigors. Successfully coping with fluctuating environments created the skills to adapt to a wider range of new environments, making it feasible for the migratory humans gradually to follow resources and herds of game into an ever widening range of habitats across the Middle East and southern Asia.
Pre-modern migrations:
Historical migration of human populations begins with the movement of Homo erectus out of Africa across Eurasia about a million years ago. Homo sapiens appear to have occupied all of Africa about 150,000 years ago, moved out of Africa 70,000 years ago, and had spread across Australia, Asia and Europe by 40,000 years BC. Migration to the Americas took place 20,000 to 15,000 years ago, and by 2,000 years ago, most of the Pacific Islands were colonized. Later population movements notably include the Neolithic Revolution, Indo-European expansion, and the Early Medieval Great Migrations including Turkic expansion. In some places, substantial cultural transformation occurred following the migration of relatively small elite populations, Turkey and Azerbaijan being such examples.
Early humans migrated due to many factors such as changing climate and landscape and inadequate food supply. The evidence indicates that the ancestors of the Austronesian peoples spread from the South Chinese mainland to Taiwan at some time around 8,000 years ago. Evidence from historical linguistics suggests that it is from this island that seafaring peoples migrated, perhaps in distinct waves separated by millennia, to the entire region encompassed by the Austronesian languages. It is believed that this migration began around 6,000 years ago. Indo-Aryan migration from the Indus Valley to the plain of the River Ganga in Northern India is presumed to have taken place in the Middle to Late Bronze Age, contemporary to the Late Harappan phase in India (ca. 1700 to 1300 BC). From 180 BC, a series of invasions from Central Asia followed, including those led by the Indo-Greeks, Indo-Scythians, Indo-Parthians and Kushans in the northwestern Indian subcontinent.
Other significant migrations include Greek migration from 728 BC, Celtic migration in Europe, Bantu migration in Africa as well as European colonial migrations in the 16th Century.
Modern Migrations – Industrialization
While the pace of migration had accelerated since the 18th century already (including the involuntary slave trade), it would increase further in the 19th century. Manning distinguishes three major types of migration: labor migration, refugee migrations, and urbanization. Millions of agricultural workers left the countryside and moved to the cities causing unprecedented levels of urbanization. This phenomenon began in Britain in the late 18th century and spread around the world and continues to this day in many areas.
Industrialization encouraged migration wherever it appeared. The increasingly global economy globalized the labor market. The Atlantic slave trade diminished sharply after 1820, which gave rise to self-bound contract labor migration from Europe and Asia to plantations. Overpopulation, open agricultural frontiers, and rising industrial centers attracted voluntary migrants. Moreover, migration was significantly made easier by improved transportation techniques.
Transnational labor migration reached a peak of three million migrants per year in the early twentieth century. Italy, Norway, Ireland and the Guangdong region of China were regions with especially high emigration rates during these years. These large migration flows influenced the process of nation state formation in many ways. Immigration restrictions have been developed, as well as diaspora cultures and myths that reflect the importance of migration to the foundation of certain nations, like the American melting pot. The transnational labor migration fell to a lower level from 1930s to the 1960s and then rebounded.
The United States experienced considerable internal migration related to industrialization, including its African American population. From 1910–1970, approximately 7 million African Americans migrated from the rural Southern United States, where blacks faced both poor economic opportunities and considerable political and social prejudice, to the industrial cities of the Northeast, Midwest and West, where relatively well-paid jobs were available.
(http://en.wikipedia.org/wiki/Human_migration#The_new_economics_of_labor_migration)
Impact of Migrations on the evolution of Habitat
Migration of human groups and population from one region to another also accelerated the evolution or transformation of human habitats. Each migrating group carried new or different traditions and technologies thereby helping transform the habitats of their new settlements. The migrations also resulted in amalgamations of groups to create larger populations, as well as conflicts. Amalgamations and population increases resulted in higher technologies further transforming architecture, agriculture and culture. For example regions historically conquered or dominated by Rome were also culturally and architecturally influenced by the Romans. When settlers from Europe migrated to America and Australia they also carried their culture, religion, technology and architecture with them and transformed the landscape of America and Australia.
One of the biggest problems of modern migration from less developed countries to highly industrialized nations as well as from rural locations to cities is the population explosion in developed countries and urban cities.
High populations in cities have accelerated the development of urban areas resulting also in the transformation of the landscape by dense construction of residential, industrial, commercial and recreational facilities and building, as well as networks of roads and rail.
The end result has been habitat destruction. Habitat destruction is the process in which natural habitat is rendered functionally unable to support the species present. In this process, the organisms which previously used the site are displaced or destroyed, reducing biodiversity. Habitat destruction by human activity mainly for the purpose of harvesting natural resources for industry production and urbanization. Clearing habitats for agriculture is the principal cause of habitat destruction. Other important causes of habitat destruction include mining, logging, trawling and urban sprawl. Habitat destruction is currently ranked as the primary cause of species extinction worldwide. It is a process of natural environmental change that may be caused by habitat fragmentation, geological processes, climate change or by human activities such as the in troduction of invasive species, ecosystem nutrient d epletion and other human activities mentioned below. (http://en.wikipedia.org/wiki/Habitat_destruction)
(http://en.wikipedia.org/wiki/Habitat_destruction)
Habitat and population
Early human settlements were dependent on proximity to water and, depending on the lifestyle, other natural resources used for subsistence, such as populations of animal prey for hunting and arable land for growing crops and grazing livestock. But humans have a great capacity for altering their habitats by means of technology; through irrigation, urban planning, construction, transport, manufacturing goods, deforestation and desertification. Deliberate habitat alteration is often done with the goals of increasing material wealth, increasing thermal comfort, improving the amount of food available, improving aesthetics, or improving ease of access to resources or other human settlements. With the advent of large-scale trade and transport infrastructure, proximity to these resources has become unnecessary, and in many places, these factors are no longer a driving force behind the growth and decline of a population. Nonetheless, the manner in which a habitat is altered is often a major determinant in population change.Technology has allowed humans to colonize all of the continents and adapt to virtually all climates. Within the last century, humans have explored Antarctica, the ocean depths, and outer space, although large-scale colonization of these environments is not yet feasible. With a population of over six billion, humans are among the most numerous of the large mammals. Most humans (61%) live in Asia. The remainder live in the Americas (14%), Africa (14%), Europe (11%), and Oceania (0.5%).Human habitation within closed ecological systems in hostile environments, such as Antarctica and outer space, is expensive, typically limited in duration, and restricted to scientific, military, or industrial expeditions. Life in space has been very sporadic, with no more than thirteen humans in space at any given time. Between 1969 and 1972, two humans at a time spent brief intervals on the Moon. As of September 2011, no other celestial body has been visited by humans, although there has been a continuous human presence in space since the launch of the initial crew to inhabit the International Space Station on October 31, 2000. However, other celestial bodies have been visited by human-made objects.
Since 1800, the human population has increased from one billion to over six billion. In 2004, some 2.5 billion out of 6.3 billion people (39.7%) lived in urban areas, and this percentage is expected to continue to rise throughout the 21st century. In February 2008, the U.N. estimated that half the world's population will live in urban areas by the end of the year. Problems for humans living in cities include various forms of pollution and crime, especially in inner city and suburban slums.Humans have had a dramatic effect on the environment. As humans are rarely preyed upon, they have been described as superpredators.Currently, through land development, combustion of fossil fuels and pollution, humans are thought to be the main contributor to global climate change. Human activity is believed to be a major contributor to the ongoing Holocene extinction event, which is a form of mass extinction. If this continues at its current rate it is predicted that it will wipe out half of all species over the next century.
http://en.wikipedia.org/wiki/World_population
***
Pavan Sukhdev talks about habitats and ecosystems